The art of glass shewing how to make all sorts of glass, crystal and enamel : likewise the making of pearls, precious stones, china and looking-glasses : to which is added, the method of painting on glass and enameling : also how to extract the colours from minerals, metals, herbs and flowers ... : illustrated with proper sculptures / written originally in French, by Mr. H. Blancourt, and now first translated into English ; with an appendix, containing exact instructions for making glass-eyes of all colours.

CHAP. CLXIV. An Excellent Preparation of Fusible Manganese to be used in making of our Red Enamel.

WE have already given sufficient direction to prepare Manganese of Piedmont, in Chap. 18. for tinging these Matters, of which we have already discours'd, but for Red and Rose-colour Enamel, there are some more exquisite Ingredients and Prepa∣rations required, which we think proper to give ac∣count of here, before we speak of the Enamel it self.

Any other than Manganese of Piedmont, will not serve your turn, for that only is fit for our use to contribute to the Fairness and Life of the Colour; take therefore equal Quantities of this Manganese and Salt-petre, as much as you please, and let them rever∣berate and calcine in an Earthen pot in your Furnace twenty four Hours; take it off and wash it well in warm Water to separate the Salt-petre, dry it well, and the Mass will be of a red Colour: To this add an equal quantity of Sal-Armoniack, grind these on a Marble with distilled Vinegar, as Painters do their Colours; dry it, and reduce it to Powder, putting it afterwards into a strong Matrass or Bolt-head of Glass, big-belly'd and long-neck'd, there to subli∣mate

about twelve Hours; break your Matrass, mix all the volatile and fixed parts together, adding the same quantity of Sal-Armoniack, as there are Flowers, and take care to weigh them before Com∣position; grind, pulverize, and sublime as before, repeating this until your Manganese remain fusible in the bottom of the Matras, and this is that which you must preserve to tinge Crystal with, and make it rud∣dy and diaphanous, or transparent as a Ruby.